(a) Technical Field
The present invention relates to a dye-sensitized solar cell including therein mesh type metal wire(s).
(b) Background Art
Recently, with growing interest on eco-friendly energy sources, there have been active studies on photoelectric conversion elements such as solar cells. Among them are dye-sensitized solar cells (DSSC), which are applicable to various industry areas including construction industry and vehicle industry.
As shown in FIG. 8, a typical unit dye-sensitized solar cell includes a working electrode, a counter electrode, and an electrolyte 170 filled therebetween. The working electrode and the counter electrode are stacked and bonded to each other by means of a bonding material 160.
The working electrode includes a transparent conductive layer 110, an oxide semiconductor thick film 120, a metal electrode 130, and a metal electrode protecting layer 140. A Fluorine Doped Tin Oxide (FTO) transparent conductive layer, for example, can be used as the transparent conductive layer 110. The transparent conductive layer 110 is coated on a surface of a transparent substrate 100 so that photoelectrons can flow through the transparent conductive layer 110. The oxide semiconductor thick film 120 is formed with porous nanoparticles. Dye molecules are adsorbed on the oxide semiconductor thick film 120. The dye molecules function to absorb light and emit electrons. The emitted electrons are to be moved to an external electrode. The metal electrode 130 is formed in a metal grid structure and acts as a collector electrode. The metal electrode protecting layer 140 (e.g., glass fit) is provided to protect the metal electrode 130 by preventing corrosion of the metal electrode 130.
The counter electrode includes a transparent conductive layer 110, a metal electrode 130; a metal electrode protecting layer 140, and a catalytic electrode 150. The transparent conductive layer 110, the metal electrode 130, and the metal electrode protecting layer 140 of the counter electrode have the same or similar structures of those of the working electrode. The catalytic electrode 150 contains a catalyst such as platinum. The electrolyte 170 can be oxidized during the operation of the dye-sensitized solar cell. The counter electrode serves to suitably reduce the electrolyte 170 in case the oxidation occurs.
If the dye-sensitized solar cell has a certain size or greater, the efficiency of the dye-sensitized solar cell may become decreased due to relatively high resistance of the transparent conductive layer 110. The metal electrode 130 is provided to minimize the decrease in the efficiency. Meanwhile, if the area of the metal electrode 130 is large, the efficiency can be less decreased, but the effective areas of the oxide semiconductor thick film 120 (photo electrode films) may be reduced, thereby lowering the overall output of the dye-sensitized solar cell
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.